A motor of the conventional large-size fan generally includes a stator base, a stator disposed on the stator base, and a rotor pivotally disposed on the stator base. The stator includes a coil, and the rotor includes a magnet. When electrical current passes through the coil of the stator, a magnetic field is produced to rotate the rotor. In order to control the rotor to rotate stably, a thermal fuse and a hall sensor are normally disposed in the motor so that the temperature and rotation speed of the motor could be sensed as a reference for control.
Generally, the thermal fuse and hall sensor are disposed on a sensing circuit board. The coil is electrically connected to the sensing circuit board. The sensing circuit board is electrically connected to a control circuit board by means of a flat cable. The power supplied to the coil is controlled by the control circuit board. The shortcoming is that when replacing the thermal fuse and the hall sensor, the sensing circuit board has to be replaced, and the sensing circuit board and the stator have to be removed together. Moreover, after replacement of the sensing circuit board, it is necessary to test whether the thermal fuse and the hall sensor are working normally. In addition, it is also necessary to test whether the coil can be powered on normally. Thus, maintenance of the conventional motor is difficult.
In view of the foregoing, the inventor made various studies to improve the above-mentioned problems, on the basis of which the present invention is accomplished.